Teache
Teache (tēch) , noun
[Compare Amer. Sp. tacha, tacho.]
(Sugar Manufacturing) Any one of the series of boilers or evaporating pans in which the cane juice is concentrated in making sugar; especially, the last boiler of the series. — Ure
The 1890 edition had the following etymology for teache: [Compare Ir. teaghaim, Gael. teasaich, to heat.]. Presumably a speculation which proved incorrect?